Conventionally, there have been known various types of room temperature-curable compositions capable of being cured into elastomer-like products at room temperature by coming into contact with the moisture in the air. Particularly, those releasing alcohols as they cure are characterized in that they do not produce unpleasant odors and corrode metals, which is why such a type of room temperature-curable compositions have been preferably used in performing sealing, bonding and coating in, for example, electric and electronic equipments.
Typical examples of the above type of room temperature-curable composition include a composition composed of a hydroxyl group-terminated polyorganosiloxane, alkoxysilane and an organic titanium compound; a composition composed of an alkoxysilyl group-terminated polyorganosiloxane, alkoxysilane and alkoxy titanium; a composition composed of a linear polyorganosiloxane containing a silethylene group(s) and terminated by alkoxysilyl groups, alkoxysilane and alkoxy titanium; and a composition composed of a hydroxyl group-terminated polyorganosiloxane or an alkoxy group-terminated polyorganosiloxane and an alkoxy-α-silylester compound (Patent documents 1 to 4).
Although these compositions exhibit a storage stability, a water resistance and a moisture resistance to a certain degree, these properties are not yet completely satisfactory. Further, these compositions have so far exhibited an insufficient fast curability.
As described above, polymers having reactive alkoxysilyl groups on their terminal ends are known. Since these polymers have their polymer terminal ends blocked by alkoxysilyl groups from the beginning, the curability of a composition containing the same is less likely to change (deteriorate) with time, and a superior storage stability can thus be achieved. Further, a workability (viscosity, thixotropy) of such composition can be arbitrarily controlled, and superior properties (hardness, tensile strength and elongation at break) can also be achieved as those polymers form elastomers through reactions with the moisture in the air and then through cross-liking reactions.
However, those of dealcoholization type have exhibited an insufficient curability, since they are less reactive with the moisture in the air as compared to those of other known curing types such as deoximation type, de-acetic acid type and deacetone type.
Here, while developments have been made on a room temperature-curable polyorganosiloxane composition superior in fast curability and capable of forming a cured product superior in moisture resistance, those that can be industrially advantageously produced have not yet been found.